Exploiting material properties to select a suitable wavelet basis for efficient rendering

Nearly-orthogonal spherical wavelet bases can be used to perform rendering at higher quality and with significantly less coefficients for certain spherical functions, e.g. BRDF data. This basis avoids parameterisation artifacts from previous 2D methods, while at the same time retaining high-frequency details in the lighting. This paper demonstrates the efficiency of this representation for rendering purposes. Regular 2D Haar wavelets can still occasionally perform better, however. This is due to their property of being fully orthogonal. An important novelty of this paper lies in the introduction of a technique to select an appropriate wavelet basis on-the-fly, by utilising prior knowledge of materials in the scene. To show the influence of different bases on rendering quality, we perform a comparison of their parameterisation error and the compression performance.